Variable angle magnetic drive



June 24, 1958 E. P. KUPKA 2,840,731

VARIABLE ANGLE MAGNETIC DRIVE Filed April 18, 1955 /6 INVENTOR.

ATTORNEY United States Patent VARIABLE ANGLE MAGNETIC DRIVE Edward P.Kupka, Berwyn, Ill., assignor to General Motors Corporation, Detroit,Mich., a corporation of Delaware Application April 18, 1955, Serial No.501,886

Claims. (Cl. 310-105) This invention relates generally to variable angledrives and more particularly to features which enable the drive to takedifferent angular positions during operation of the drive.

Quite often in the use of rotatable booms, as for example booms fordredges and the like, it is common to provide a separate drive motor orengine directly on the boom as a means for driving a cutting head.Although the present invention is not so limited, one of its possibleapplications would be for the elimination of such a separate drive motoror engine directly from the boom.

It is, therefore, an object of the present invention to provide auniversal angle drive between driving and driven members whose driveangle can be varied over a wide range during the course of operation ofthe driving and driven members.

This and other objects of the invention will appear in moreparticularity upon reference to the accompanying detailed descriptionand drawing, in which:

Fig. 1 represents an application of the invention and illustrates theuse of the drive between a driving motor and the cutting head carryingboom of a dredge.

Fig. 2 is an enlarged side view in elevation of the novel variable angledrive illustrating .how the use of gimbal pieces allows the widelyvariable operating positions of the drive.

Fig. 3 is an end view in elevation further illustrating the use of thegimbal pieces.

Fig. 4 is a plan view in section taken on the line 44 of Fig. 3 alsoillustrating the use of the gimbal pieces and other details of the angledrive.

Referring now to the drawing and particularly to Fig. 1, a dredge 2 isshown having a derrick 4 mounted thereon. Below the derrick 4 is a drivemotor 6 which by means of the novel universal angle drive indicatedgenerally by a numeral 8 is operatively connected to a rotatable dredgeboom 10. As indicated by the broken lines in Fig. l, the boom 10 ismovable in a conical manner by means of guys 12. The boom is providedwith a cutting head 14.

Referring now to Figs. 2, 3 and 4, it will be observed that the boomshaft is adapted to be rotated about its longitudinal axis by the drivemotor 6 through the universal angle drive indicated generally by thenumeral 8. This drive includes includes a pair of transversely spacedsupports 16 in which the trunnions 18 of a gimbal ring or piece 20 aresupported for movement of the ring about an axis 22 extending throughthe point 24. A second gimbal piece or ring 26 is supported by means oftrunnions 28 for movement about an axis 30 in the same plane as the axis22 and at right angles thereto. Axis 30 also extends through the point24. The gimbal piece 26 is provided with a circular bearing opening 32whose axis also extends through the point 24 and is always perpendicularto the axis 30. Iournaled for rotation in the opening 32 is one end ofthe dredge boom 10 which has fixed thereon a spherical driven couplingmember 34. Coupling member 34, as already mentioned, is spherical2,840,731 Patented June 24,1958

in shape and has inner and outer spherical surfaces 36 and 38,respectively, which are generated by radii about the point 24. Themember 34 is of magnetizable material and forms the inductor ring of aneddy current coupling. Fixed on an extension 40 of the drive shaft ofthe driving motor 6 is a female member 42 having a plurality ofinterdigitated poles 44. The poles 44 are provided with convex sphericalsurfaces 46 generated by equal radii about the point 24. Since thespherical surfaces 38 and 46 have been generated about centerscoincident with each other and the surfaces have been spaced from eachother by an air gap 48, this air gap is uniform throughout between thesesurfaces. The poles 44 are interlaced about a field exciting coil 50which may be energized through suitable slip rings, not shown, togenerate a toric flux which interlinks both members 34 and 42 and passesthrough the polar members 44 and the inductor surface 38 and the polarmembers 44 which also are magnetic. It will be observed that the axis ofrotation of the shaft 40 and of the polar member 42, as well as thefield exciting coil 50, also extend through the point 24.

By combining this spherical eddy current coupling with a pair of gimbalpieces, an infinitely variable universal angle drive has been providedwhose angle can be varied during operation of the drive therebyachieving a flexibility of operation, as for example in the boom of adredge, which heretofore was not available. It will be observed thatthis infinitely variable drive includes no mechanical parts actuallyconnecting the driving member with the driven member of the drive andthat all of the weight of the boom is taken up through the gimbal pieces20 and 26 and the supports 16 thereby placing no loading strains orstresses on the drive itself, whose sole function, then, is to drive theboom.

What I claim is:

1. A constant velocity ratio universal coupling for effecting a variableangle mechanical drive comprising a support, male and female driving anddriven members rotary on variable angled axes having an intersectingpoint, a gimbal piece on said support oscillatory about an axis throughsaid point during driving of said driven member by said driving member,a second gimbal piece mounted on said first gimbal piece oscillatoryabout an axis through said point perpendicular to the axis of movementof said first gimbal piece during driving of said driven member by saiddriving member and journaling one of said members, one of said membershaving flux concentrating polar members the outer peripheries of whichare define-d spherically with a center substantially at said point, theother member having an adjacent relatively uninterrupted inductorsurface also defined spherically with a center substantially at saidpoint, the resulting spherically defined polar peripheries of the fiuxconcentrating polar members and said spherically defined conductorsurface being spaced by means of a constant spherical air gapirrespective of the angle of said axes, and at least one annularexcitation coil carried on one of said members in a plane substantiallyperpendicular to its axes of rotation and generating a toric flux fieldinterlinking both of said members and passing through said polar membersand through said inductor surface, the inductor surface and the polarmembers being magnetic.

2. A constant velocity ratio universal coupling for effecting a variableangle mechanical drive during operation of said drive comprising asupport, male and female driving and driven members rotary on variableangled axes having an intersecting point, a gimbal piece on said supportoscillatory about an axis through said point, a second gimbal piecemounted on said first gimbal piece oscillatory about an axis throughsaid point perpendicular to the axis of movement of said first gimbalpiece and jonrnaling said male member, one of said members having fluxconcentrating polar members the outer peripheries of which are definedspherically With a center substantially at said point, the other memberhaving an adjacent relatively uninterrupted inductor surface alsodefined spherically with a center substantially at said point, theresulting spherically defined polar peripheries of the fluxconcentrating polar members and saidspherically defined conductorsurface being spaced by 'means of aiconst'ant spherical air gapirrespective of the angle of said axes, and at least one annularexcitation coil car ried on one of said members in a plane substantiallyperpendicular to its axes of rotation and generating a toric flux field.interlinking .both of said members and passing through said polarmembers and through said inductor surface, the inductor surface and thepolar members being magnetic. a

'3. -In combination with an eddy current coupling including spacedmagnetic spherical rotatabledriving and driven members having a commonpoint about which their ,spaced spherical surfaces are generated, asupport, and a universal joint supporting one of said members foruniversal movement about said point during'drivingtof the driven memberby the driving member.

4. In combination with an eddy current coupling including spacedmagnetic spherical rotatable driving and driven members, a support,

'4 and a universal joint'support ing one of said members for universalmovement relative to the other of said members during driving of thedriven member by the driving member.

5. In combination, an eddy current coupling including spaced magneticspherical rotatable driving and driven members, said members having acommon point about Which their spaced surfaces are generated, a support,a gim'bal piece oscillatory on said support about an axis, asecondgimbal piece oscillatory with respect to said first gimbal pieceabout an axis intersecting said first axis at right angles thereto andmeans journaling one'of said members in said second gimbal piece forrotation about an axis. perpendicular to and extending through theintersection of said first two axes.

References Cited in the file of this patent UNITED STATES PATENTS GreatBritain Oct. 22, 19 11

